The battle for the future of the Open Web is taking place as a new document model merges into a platform for highly graphical, interactive and information rich applications. Open source communities vie with dominant vendors Adobe, Microsoft, Apple, Cisco, Nokia and Google to stake out their claims as open source innovations collide with standards consortia and proprietary alternatives.

Stingrays operate by mimicking a cell tower and directing all cellphones in a given area to route communications through the Stingray instead of the nearby tower. They are especially pernicious surveillance tools because they collect information on every single phone in a given area—not just the suspect’s phone—this means they allow the police to conduct indiscriminate, dragnet searches. They are also able to locate people inside traditionally-protected private spaces like homes, doctors’ offices, or places of worship. Stingrays can also be configured to capture the content of communications.

Because Stingrays operate on the same spectrum as cellular networks but are not actually transmitting communications the way a cell tower would, they interfere with cell phone communications within as much as a 500 meter radius of the device (Baltimore’s devices may be limited to 200 meters). This means that any important phone call placed or text message sent within that radius may not get through. As the complaint notes, “[d]epending on the nature of an emergency, it may be urgently necessary for a caller to reach, for example, a parent or child, doctor, psychiatrist, school, hospital, poison control center, or suicide prevention hotline.” But these and even 911 calls could be blocked.

The Baltimore Police Department could be among the most prolific users of cell site simulator technology in the country. A Baltimore detective testified last year that the BPD used Stingrays 4,300 times between 2007 and 2015. Like other law enforcement agencies, Baltimore has used its devices for major and minor crimes—everything from trying to locate a man who had kidnapped two small children to trying to find another man who took his wife’s cellphone during an argument (and later returned it). According to logs obtained by USA Today, the Baltimore PD also used its Stingrays to locate witnesses, to investigate unarmed robberies, and for mysterious “other” purposes. And like other law enforcement agencies, the Baltimore PD has regularly withheld information about Stingrays from defense attorneys, judges, and the public.

Moreover, according to the FCC complaint, the Baltimore PD’s use of Stingrays disproportionately impacts African American communities. Coming on the heels of a scathing Department of Justice report finding “BPD engages in a pattern or practice of conduct that violates the Constitution or federal law,” this may not be surprising, but it still should be shocking. The DOJ’s investigation found that BPD not only regularly makes unconstitutional stops and arrests and uses excessive force within African-American communities but also retaliates against people for constitutionally protected expression, and uses enforcement strategies that produce “severe and unjustified disparities in the rates of stops, searches and arrests of African Americans.”

Adding Stingrays to this mix means that these same communities are subject to more surveillance that chills speech and are less able to make 911 and other emergency calls than communities where the police aren’t regularly using Stingrays. A map included in the FCC complaint shows exactly how this is impacting Baltimore’s African-American communities. It plots hundreds of addresses where USA Today discovered BPD was using Stingrays over a map of Baltimore’s black population based on 2010 Census data included in the DOJ’s recent report:

The Communications Act gives the FCC the authority to regulate radio, television, wire, satellite, and cable communications in all 50 states, the District of Columbia and U.S. territories. This includes being responsible for protecting cellphone networks from disruption and ensuring that emergency calls can be completed under any circumstances. And it requires the FCC to ensure that access to networks is available “to all people of the United States, without discrimination on the basis of race, color, religion, national origin, or sex.” Considering that the spectrum law enforcement is utilizing without permission is public property leased to private companies for the purpose of providing them next generation wireless communications, it goes without saying that the FCC has a duty to act.

But we should not assume that the Baltimore Police Department is an outlier—EFF has found that law enforcement has been secretly using stingrays for years and across the country. No community should have to speculate as to whether such a powerful surveillance technology is being used on its residents. Thus, we also ask the FCC to engage in a rule-making proceeding that addresses not only the problem of harmful interference but also the duty of every police department to use Stingrays in a constitutional way, and to publicly disclose—not hide—the facts around acquisition and use of this powerful wireless surveillance technology.